The investigators have developed a modified Spearman estimator for a location or scale parameter for use in small-sample bioassay (dose-response experimentation), and have made a detailed study of application of this estimator to problems where the probability model is exponential, a case which arises in serial-dilution experiments. As part of the current project, the investigators have extended their previous work to obtain small-sample hypothesis tests and confidence intervals for a location or scale parameter, and to show that exact distributions for the related statistics can be computed. The proposed research will extend these methods to small-sample bioassay problems in which both location and scale parameters are unknown, and to other problems involving one-parameter dose-response models. Small-sample properties of the methods derived will be studied using a computer, and a comparison made with similar methods based on maximum likelihood estimators. Specific applications will be formulated for problems involving the exponential, normal, and logistic probability models, which are the most commonly used in practice. The statistical techniques produced will be in a form directly usable by biomedical research workers who are not specialists in statistics. Standard methodology of statistical theory and computation will be employed throughout the project.